"The problem has to be resolved within a month," Russian Aerospace Agency director Yuri Koptev said during a seminar with Italian government officials and aerospace executives in Moscow.
Koptev said Russia was ready to build extra spacecraft but needs financial support from the United States and other partners in the 16-nation space station project. New ships take at least 14 months to build and they won't be ready in time if an agreement isn't reached soon, he said.
Russian Soyuz capsules and Progress cargo ships remain the only link to the space station following the Columbia shuttle disaster and the suspension of shuttle flights pending the investigation.
But NASA says potential funding is constrained by U.S. legislation barring additional payments to Russia's space agency unless the United States confirms Russia has not transferred missile technology or nuclear, chemical or biological weapons to Iran in the past year.
Koptev acknowledged "political limitations" on the U.S. side but expressed hope that the issue would be resolved and said it was being discussed on the "presidential level."
Russia has budgeted $130 million to fulfill its obligation to send two Soyuz and three Progress ships this year to the station, which has a crew of two American astronauts and a Russian cosmonaut. It needs additional funds to finish construction of extra Soyuz capsules and Progress ships needed because of the loss of shuttle flights.
By Eric Engleman